With sympy, I am aware you can you do something like this:
In [37]: sqrt(8) / sqrt(27)
Out[37]: 2*sqrt(6)/9
In [38]: pprint(sqrt(8) / sqrt(27))
2⋅√6
────
9
There is a complex number I would like to represent in the same "symbolic" manner:
In [39]: z = complex(1,2)
The length:
In [42]: Abs(z)
Out[42]: 1.73205080756888
Now I would like to represent that number as :
In [46]: pprint(sqrt(3))
√3
Don't use the complex type as that can only represent complex numbers using floating point. Instead use SymPy's I:
In [1]: from sympy import I
In [2]: z = 1 + 2*I
In [3]: z
Out[3]: 1 + 2⋅ⅈ
In [4]: abs(z)
Out[4]: √5
Also worth noting that sometimes SymPy can convert a float back into a guessed symbolic form:
In [5]: e = abs(complex(1, 2))
In [6]: e
Out[6]: 2.23606797749979
In [7]: from sympy import nsimplify
In [8]: nsimplify(e)
Out[8]: √5